Process for preparing derivatives of acid sludges



MM July 25, 1944 PROCESS FOR PREPARING DERIVATIVES OF ACID SLUDGES Jere C. Showalter, Goosecreek, and Mchemet Wiggen, Baytown, Ten, assitnors to Standard Oil Development Company, a corporation of Delaware No Drawing. Original application September 1,

1939, Serial No. 293,050. Divided and this application December 31, 1941, Serial No. 425,036

' 6 Claims. (01. 196-34) This invention relates to improvements in products obtained from hydrocarbon oil acid sludge and more particularly from the sludges obtained on treating cracked hydrocarbon naphthas with sulfuric acid.

This is a divisional case of patent application Serial No. 293,050, filed September 1, 1939.

It is well known that hydrocarbon oil acid sludges that are separated from the hydrocarbon oils contain substantial amounts of hydrocarbons together with the spent sulfuric acid. These hydrocarbon oil acid sludges, on dilution with water and maintaining at an elevated temperature, separate into two layers, one a dilute acid layer and the other an oil layer. This oil layer has been further purified by neutralization and fractionation to produce hydrocarbon oils which may be used 'as drying oils. The objection to this process is that the hydrocarbon oil thus prepared is a dark, discolored oil and even though it is treated with a decolorizing clay, the oil is not suitable for use in paints due to its dark color and incompatibility with lead driers.

An object of this invention is to prepare from hydrocarbon oil acid sludges a drying oil and a resin which may be used in light colored paints and/or varnishes.

According to the preferred embodiment of this invention, a cracked naphtha or a hydrocarbon naphtha that contains a large percentage of unsaturated hydrocarbons is treated with strong sulfuric acid. After 'the mixture of acid and cracked naphtha is agitated for a sufficient time to complete the reaction of sulfuric acid on the unsaturated or other highlyreactive constituents of the cracked naphtha, it is allowed to settle and the acid sludge layer separates to the bottom and is withdrawn from the "treated naphtha. This acid sludge is mixed with suificient water to hydrolyze the esters and is allowed to settle into two layers and the bottom layer of mineral acid is removed.

The upper or oily layer is then neutralized by washing with an aqueous solution of sodium carbonate or other alkali. The washed oil is then mixed with 4 to 5 volumes of propane or other liquefied saturated hydrocarbon compounds that are normally gaseous at ordinary temperature for each volume of the oil and maintained at a temperature of F. for about 30 minutes. A layer of carbonaceousmaterial settles out and is removed. Aiter removal of the propane by vaporization, the decarbonized oil is subjected to fireand-steam or vacuum distillation and an overhead fraction boiling between about 520 and 650 F. at normal atmospheric pressure is recovered as a crude drying oil. A residue of resin bottoms is withdrawn from the still. The percentage of drying oil distillate varies from 30 to 47 per cent based on the oil separated iro cracked naphtha acid sludge.

The drying oil distillate and the resin separately (the latter in naphtha solution) are one pound of clay per gallon at about 300 F. for

a short period of time ranging up to about 30 minutes. After separation of the clay by filtration, the drying oil can then be used as such or with the addition of a drier, such as lead or manganese naphthenate or oleate, etc. The naphtha solution of resin is contacted with about 2 pounds of clay per gallon of resin (naphtha-free basis) at atmospheric temperature for approximately 30 minutes. The filtered resin solution is then subjected to distillation to remove the naphtha. It may sometimes be desirable to treat the acid-treated drying oil and acid-treated resin with propane before clay treating. The lightcolored finished resin may be used in varnish manufacture.

When a maximum yield of drying oil is desired:

' the original naphtha sludge must be hydrolyzed the acid state for a relatively long period of time,

the drying oil tends to polymerize and form a larger yield of resin than in the above-mentioned instance. When a maximum yield of resin is the desired product, on the other hand, the original naphtha sludge is allowed to remain in the unhydrolyzed state for a relatively long period of time.

If the hydrolyzed sludge containing small percentages of free mineral acid is permitted to remain in contact with this free acid for a relatively long period of time, a tendency for the drying oil to polymerize to resin persists. Consequently, if the free acid is not removed by other means which will be described later, it is preferred to neutralize the hydrolyzed oily layer promptly with aqueous sodium carbonate or other alkali in order to check further polymerization. However, this neutralization step introduces undesirable salts which cannot be removed by simple water washing due to severe emulsion difficulties. Nevertheless, if these salts are not removed prior to the distillation step, they decompose and release sulfur compounds which are corrosive to the distillation equipment and result in theproduction of drying oils which are incompatible with lead driers.

The objectionable salts andsome carbonaceous or asphaltic material can be readily precipitated and removed by dissolving the neutralized oily layer in 4 to 5 volumes of propane or other liquefied normally gaseous hydrocarbon at approximately 120 F. If it is convenient to propane treat the hydrolyzed oily layer immediately, the neutralization step may be omitted. Since propane treatment precipitates the traces of free mineral acid and acidic esters along with thecarbonaceous material, polymerization of the crude drying oil is effectively checked and subsequent distillation and refining may be delayed. Whereas considerable quantities of free sulfur begin to be liberated at about 320 F. when distilling-non-propane treated, hydrolyzed or neutralized sludge, no harmful quantity of free sulfur or sulfur dioxide is observed during the distillation of'propane treated oil.

Although it is preferred to separate during distillation a light fraction boiling below about 520 F. in order that the finished drying oil may conform to certain specifications for commercial drying oils, portions of the lower boiling fraction which also have drying and thinning properties may be included in the finished drying oil.

The crude drying oil distillate is preferably refined by treating it with about 50 pounds of equivalent 98% sulfuric acid per barrel of oil and,

after separating the resulting secondary sludge, to contact the acid oil with about one pound of clay per gallon of oil at a temperature of approximately 300 F., in conventional manner. It was found, however, that quantities as low as 15 pounds of acid per barrel can be used to produce a finished oil of desirable color provided the clay dosage is appreciably increased. An oil of desinable color quality cannot be produced economically by simple clay treatment in the absence of a prior acid treat. Variation of the acid treat between the above-mentioned limits does not adversely affect the drying properties of the oil.

The combined drying oil and resin fractions may be acid and clay treated, although the yield of resin is lowered and the color of the drying oil fraction is appreciably decreased over those ob- ,tained in the preferred procedure.

It has been shown in the prior art that resins prepared from sludges obtained in the aluminum chloride treatment of cracked naphthas or other highly unsaturated hydrocarbon fractions may be refined by fluxing with a light non-aromatic hydrocarbon fraction and contacting with an activated clay at temperatures in the range of about 200 to,450 F. for short periods of time, on the order of 5 to 10 minutes. This treatment produces some improvement in color of the resins obtained from sulfuric acid sludges of cracked naphthas, but it does not yield as light colored product as does that prepared by this preferred process of removing carbonaceous and acidic material by propane precipitation, acid treating in two volumes of naphtha with about 100 pounds of acid per barrel (unfluxed basis), and contacting with about two pounds of activated or non-activated clay per gallon (unfluxed basis) at room temperature while still in naphtha solution. The following examples clearly illustrate the results of these treatments:

EXAMPLE 1 EXAMPLE 2 One hundred grams of the crude resin prepared in Example 1 were fluxed with 500 cc. of a narrow-b'oiling-range, non-aromatic naphtha and 100 grams of Super Filtrol (activated) clay were added. After warming the mixture to 200 F. and agitating for 10 minutes, the clay was filtered out and the naphtha stripped off, The recovered resin had an absolute color of 5100,

EXAMPLE 3 One hundred grams of the crude resin prepared in Example 1 were crushed and mixed with 100 grams of Super Filtrol clay. After heating the mixture to 450 F. and stirring for 5 minutes, it was cooled and fluxed with 500 cc. of nonaromatic naphtha so that the clay could be separated by filtration. The stripped resin had an absolute color of 1370.

EXAMPLE 4 A portion of the crude resin prepared in Example 1 was fluxed with two volumes of a nonaromatic naphtha and treated with 100 pounds of 98% sulfuric acid per barrel based on the unfiuxed crude resin. After separating the acid sludge, the fiuxed mixture was agitated at F. for 30 minutes with two pounds of Milwhite No. 2 (non-activated) clay per gallon based on the unfiuxed acid treated resin. The filtered and stripped product had an absolute color of 584.

In the foregoing examples the absolute color of the resin was determined by dissolving a one gram sample of the filtered and naphtha-free,

disc and reading the scale'within the nearest millimeter. This observed color was then converted to absolute units and the latter were .multiplied by the number of cubic centimeters of naphtha used for dilution. Conversions of Robinson color to absolute color were obtained from a graph wherein the following are specific points:

Robinson color col EXAMPLE The advantages of propane treating in preparing light-colored drying oils and resins from hydrolyzed naphtha acid sludge oil are illustrated in Table I. In case A of Table I, a sample of acid sludgewas hydrolyzed and the decanted oily layer was water washed and soda neutralized. The oily material was then fire-and-steam distilled into a heavy naphtha cut, a drying oil distillate and a crude resin bottoms. The drying oil distillate and the crude resin bottoms (the latter in naphtha solution) were subsequently treated with acid and clay for improvement in color. In case B of Table I, a sample of the acid sludge was hydrolyzed and the decanted oily layer was water washed but not neutralized. The resultant hydrolyzed sludge oil was decarbonized by treating with liquid propane. precipitated asphaltic material and flashing off the propane, the decarbonized oil was fire-andsteam distilled into a heavy naphtha out, a drying oil distillate and a crude resin bottoms. This drying oil distillate and crude resin bottoms were subjected to acid and clay treatment just as in case A. The finished drying oil and resin of case B are sufiiciently light in color to be used inthe preparation of light-colored paints and/or light-colored varnishes, whereas the products of case A are too dark'in color for such usage.

Table I Cracked naphtha acid sludge :53: Case B propane 2 223 treated Treating conditions for acid sludge: Temperature of hydrolysis F 160 170 Hydrolyzing ratio, sludge to water 1:1 1:1 Treating conditions for hydrolyzed sludge 011:

Water washing ratio, sludge Oll to watch. 1:1 1:1 Soda for neutralization l- None [)eearbonization ratio, propane to sludge v 41 oil Decarbonization temperature. 120 Yield of neutralized or decarbonized O1], per cent hydro. sludge o1 l 79.4

Atmospheric steam distillation of treated sludge oil: it 0 Still temperature for naphtha cut. F. 320-420 220-555 Still temperature for drying oil cut. .do. 420-650 555-650 Yield of naphtha ..volume per cent 24. 3 28. 4 Yield of drying oil distillate do. 51.8 47. 8 Yield of resin bottoms ..do. 23.9 23.8

After separating the Cracked n hthe acid at.

Oeee B m 3 3* mm Treatment, yields and quality oi drying oil:

Pounds 98% E380 per barrel drying oil liit tazz fi 83% M c rea empera ure Yield of acid treated drying oil, hydrolyzed sludge oil. j ..volume r cent.. 37. 7 27. 6 Pounds non-activated clay per acid oil. 1. 0 1. 0 Temperature of contact 300 300 Time of contact -.minutes.- 30 30 Yield of clay contacted oil, hydrolyzed sludge oil --volume per cent.. 33. 9 2e. 6 Gravity A. P. 16.0 11.1 Flash F 286 250 Viscosity at 100 F., Saybolt Universal.-.. 345 187 Viscosity at 210 F., Saybolt Universal. 45. 7 40. 4 Color, Robinson 4 7}: Saponlflcation number 1. 54 1. Acid number (neutralization value) 0. 25 0. 14 Iodine number.- 208 293 Carbon residue per cent.. 0. 4 0. 22 m do 1.2 1.3

Drying time, hours exposed to direct sunlight 4 5 Treatment, yields and quality of resin bottoms:

- Fluxing ratio, resinznapht a 1:2 1:2

Pounds 98% HSO per barrel resin, (unfluxed basis) 100 100 Pounds non-activated clay per gallon resin (unfluxed basis) 1.5 2.0 Temperature of contact... F" 85 Time of contact -minutes 30 30 Yield of clay-contacted, naphtha-free resin, hydrolyzed sludge oil volume per cent 20.0 11. 8 Specific gravity 0. 991 Absolute color 2740 786 Ring and ball softening point F 17 186 Slight excess.

EXAMPLE 6 In the following Table II, case A illustrates the type of products obtained by a preferred method of making drying oils and resins from hydrolyzed cracked naphtha acid sludge oil. A sample of unneutralized oily material from freshly hydrolyzed cracked naphtha acid sludges was decarbonized by propane treatment and then distilled into a naphtha cut, a drying oil distillate and a crude resin bottoms. The dryingoii distillate and the crude resin bottoms (the latter in naphtha solution) were then treated with strong sulfuric acid and subsequently contacted with non-activated clay. Both products were'light in color, the drying oil being satisfactoryjfor use in the preparation of light-colored paints and varnishes,- and the resin being satisfactory for use in the preparation of light-colored varnishes.

Case B illustrates the impossibility of producing economically a light-colored drying 011 without acid treating the 'crude product. The

treating procedure employed in this case differs from that of case A only in the respect that no acid was used on the crude drying oil distillate; instead, an excessively large clay treat was employed in an unsuccessful attempt to decolorize satisfactorily the distillate.

Case 0 illustrates the type of products obtainable from a hydrolyzed cracked naphtha acid sludge oil which had been neutralized and aged several days before subjecting it to propane. acid and clay treatment in accordance with the procedure of case A. In this particular example, the hydrolyzed acid sludge oil was neutralized with sodium carbonate and allowed to age 16 days prior to completion of .the treatment for converting it into a drying oil and a resin.

Table I! Freshly hydro] cracked Charge "8* mph. ac sludge I Case. A B C be Unnen- Unnen- Unneu- Condition when propane decor niled ma Rati one: hydrolysed 4:1 4:1 4:1 Deca r b F. 1m m 11 Yield of decarbonize oil-.'

pereent.. 79. 4 79.4 87,0 Atmospheric steam still temp. F. naph. u t. mm m-5m mm Atmospheric steam still temp. F- ry l 011 m 556 660 520-650 til-660 Yield oi naphtha "perc nt" 22. 5 23. 5 25. Yield 01 drying oil distilla 38. 0 36. 4 41. 8 Yield oi resin I 18. 9 l9. Z). 2 Treatment, yields and quality 01 drying oil: Pounds 987 suliuricacld/barrel drying oil distillate. 50 I o 50 Yield oi acid treated a o s 32,5 Pounds non-activated y/gal. acid oil 1.0- 2.0 1. 0 Contacting temperature. 300 300 Y 300 Time of f 30 30 Yield of clay contactedoil... i 30. 8 34. 2 31; 2 Gravity, 9A. P 1..-. 17. 7 l7. 7 l7. 1 PHIL... 25 m m Saybolt viscosity at 100 F -seoonds. v 187 214' 329 Be bolt viscosity at 210 F do 40. 4 41. 5 44. 5 C or, Robinson..--- v 7% 1% 9+ 8| niilcation number---'. 1.6 0.84 o, 4' Acid number (neut. value). .0. 14 0. 2 0. 14 Iodine number. 293 325 290 Carbon residue -peroent 0. 22 0. 3s 0 29 1. 3 1. 5 L 3 Drying time hours exposed to direct sunligh a g I 6 Treatment, yields and qualitg of resin bottoms:

Ratio c'ruderesin: naplit aflux 1:2 1:2 1 2 Form 98% suliuric acid/barrel resin (unfiuxed). 100 0o 100 Yhld of acid treated resin (unfluxed) l4. 0 14. 0 14. 8 Pounds non-activated clay/gal. resin (unfluxed) 2.0 2.0 2. 0 Contacting temperature 85 85 Time of contact 3 30 v 30 Yield oi clay contacted,-naphtha-iree resin.. 13. 2 13. 2 13. 9 Specific gravity 0. 991 0. 991 D. 985 Abeolutecolornnh. 786 584 Ring-and-ball soiteningpoint 185 186 195 NorI.-A1l yields calculated onbasis oi water and acid-irco hydrolyzed sludge.

a wide variety of other uses, such as those hereinaiter mentioned. v The drying oil may be used in the preparationoi paints and varnishes'oi all kinds, adhein.

sives, putties, printing inks, and waterproofing compounds for brick, tile, stucco, or concrete buildings. It may also be'used" for waterproofing fabrics, for'an adhesive in briquetting, and use substitute in certain instances for natural drying or semi-drying oils.

The resin may be used'in pigmented tiles, floor covering, roofing material, panel boards, moulding powders, and waterproofing compounds for brick, tile, stucco, or concrete walls or fioors; furthermore, it may be used in almost all lac-' quers, varnishes, paints and aliiedmaterials, the resin may be used also for electrical insulation,- iorsizing fabric or paper,as a protective covermg for pipe lines, and as San impregnant for improving the appearance, strength and waterproofing qualities of cardboard, fibre board, or

' wood: In the unrefined state, resins obtained from hydrolyzed cracked naphtha acidsludge oil are particularly well adapted for use in the man- 5 ,uiacture of ,clay pigeons? for eampie, the

acid sludge obtained byv contacting cracked hydrocarbon nanhthas with sulfuric acid to form a layer of aqueous vacid solution and an oily 7t layer, removing an aqueous acid solution. treating the oily layer with a liquefied normally gase ous hydrocarbon to form a precipitate, separating the precipitate from the remaining liquid,.

distilling the remaining liquid to separate the hydrocarbons boiling below about 650 F. from a residual bottom fraction, dissolving theresidual bottom fraction in. a volatile hydrocarbon oil, treating the resulting solution witl'rsuliuric acid, separating the sulfuric acid sludge formed there by and contacting ther'esidual solution-with clay,

separating the clay from the residual solution acid sludge obtained by contacting cracked hydrocarbon naphthas with sulluric acid to form I a layer of aqueous solution and an oily layer, re-,

moving the aqueous solution, treating the oily layer with at least 4 volumes of propane for each volume of-oil to form a precipitate, separat ing the precipitate from the remaining oil, distilling the remaining oil to separate'the oil boiling below about 650 from a residual bottom fraction, dissolving the residual bottom fraction in a saturated hydrocarbon naphtha; treating the resulting solution 'with 98% sulfuric acid in an amount upward to about 100 pounds per barrel based on the residual bottom fraction, separating the acidsludge formedthereby contact- 'ing the residual acidic solution with about 2 pounds of decolorizing clay per gallon of resid- -ual bottom at a temperature of approximately 85 F., separating the clay from said solution and distilling oil? the naphtha from said solution.

3. A process of preparing derivatives of an acid sludge which comprises treating at a temperature from to F.-with water an acid sludge obtained by contacting cracked hydror 2,354,554 carbon naphthaswith sulfuric acid'to formsr layer of aqueous solution and an oil layer, removing the aqueous solution, treating the oily layer with 4 to 5 volumes of propane for. each volume of oil to form aprecipitate, separating theprecipitate formed thereby from the .remaining oil, distilling the remaining oil to separate the. oil boiling below 650 F..from a residual bottom fraction, dissolving the residual bottom fraction. in a saturated hydrocarbon. naphtha, treatingtheresulting solution with 100 pounds of 98% sulfuric acid per barrel based on the residual bottom fraction, separating the acid sludge formed thereby, contacting the residual acidic solution with 2 pounds of decolorizing clay per gallon of residual bottom at a temperature of approximately 85 F., separating the clay from said solution and distilling oil the naphtha from said solution.

4. A process for preparing a drying oil which comprises treating with water an acid sludge obtained by contacting cracked hydrocarbon naphthas with sulfuric acid, removing an aqueous acid solution, treating the residual oil with a liquefied, normally gaseous hydrocarbon, senaratingthe resulting precipitate, distilling the remaining oil, and recovering fr'om the overhead fraction a crude drying oil boiling between about 520 and 650, F.

5. A process for preparing valuable} derivatives from -an i acidv sludge obtained by contacting,

cracked hydrocarbonnaphthas with sulfuric acid which comprises treating the acid sludge with water to form a layer of aqueous acidic solution and an oily. layer, removing the aqueous acidic solution, treating the oily layer with a liquefied,

normally gaseous hydrocarbon to form a precipitate, separating the resulting precipitate from the remaining oil, distilling the remaining oil to remove constituents boiling up to about 650 F. from residual bottoms, subjecting the residual bottoms to a sulfuric acid treatment to form an acid sludge, removing the acid sludge, and neutralizing the remainder.

6 A process for preparing .a drying oil from an acid sludge obtained by contacting cracked hydrocarbon naphthas with sulfuric acid which comprises treating said sludge with water within a few hours after its formation, removing the 

